CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT > Fluent Multiphase

VOF with evaporation and condensation UDF's

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 13, 2015, 21:57
Default VOF with evaporation and condensation UDF's
  #1
Member
 
G. S.
Join Date: Nov 2010
Posts: 54
Rep Power: 12
gerardosrez is on a distinguished road
Hello colleagues,

I have a question for those who know Fluent from its inside...

The VOF model theory states that only mass conservation equation is solved for secondary phases, therefore they called them the volume fraction conservation equations....At the end the primary phase volume fraction is the unity less the sum of secondary phases mass fractions....

So if I implement UDF to model evaporation and condensation (for example: water) mass sources, why should I have to write UDF for both cond/evap mass sources for primary phase if it is going to be calculated after volume fractions of secondary phases are done...


Best regards...
gerardosrez is offline   Reply With Quote

Old   February 16, 2015, 13:07
Default
  #2
Senior Member
 
navid
Join Date: Jan 2010
Posts: 110
Rep Power: 12
ndabir is on a distinguished road
Can't you just use the evaporation-condensation option for mass transfer in the phase interaction toolbar instead of using a UDF?

When I use VOF, the evaporation-condensation option for mass transfer is available and can be used. I use Ansys Fluent 13. Maybe this option is not available in other versions of the software.
ndabir is offline   Reply With Quote

Old   February 20, 2015, 04:22
Default
  #3
Senior Member
 
kbaker's Avatar
 
Khalid Baker
Join Date: Mar 2009
Location: IRAQ
Posts: 168
Rep Power: 13
kbaker is on a distinguished road
Hello guys I have a question : is the evaporation-condensation option work properly with VOF model?
kbaker is offline   Reply With Quote

Old   March 14, 2015, 20:37
Default
  #4
Member
 
G. S.
Join Date: Nov 2010
Posts: 54
Rep Power: 12
gerardosrez is on a distinguished road
Dear colleagues thanks for your answers....

I found this in the User's Guide...
  1. evaporation-condensationenables you to apply the evaporation-condensation model as the mass transfer mechanism. This model is available with the mixture and Eulerian multiphase models. Refer to Evaporation-Condensation Model in the Theory Guide for a theoretical discussion about this model.
According to this the evaporation-condensation model is not available to be used with VOF simulations...I know you can select it from the User Inteface but it seems that it does not work....

Even if this is available or not, I'd like to consult the main question of my post which is what happens with the mass source calculated, by a UDF, for primary phases if no vof equation is solved for this one...

Best regards...and again thanks for your answers....
gerardosrez is offline   Reply With Quote

Old   March 15, 2015, 16:01
Default
  #5
Senior Member
 
kbaker's Avatar
 
Khalid Baker
Join Date: Mar 2009
Location: IRAQ
Posts: 168
Rep Power: 13
kbaker is on a distinguished road
Dear gerardosrez thanks for illustration. About your question if you not use vof model so what model of multiphase flow you tried? furthermore selecting which of the phases be primary or secondary that is your choice and you can set any of the phases as primary or secondary as you like? I think your question seems obvious something?

kbaker
kbaker is offline   Reply With Quote

Reply

Tags
condensation, evaporation, mass source, udf, vof

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Evaporation & Condensation model Amit FLUENT 0 September 7, 2012 07:53
evaporation and condensation in Fluent aximefu FLUENT 4 May 12, 2012 10:47
Question:Considerations about the evaporation in VOF dokeun FLUENT 10 February 24, 2011 21:47
Water Evaporation and condensation modeling Linjie CFX 6 May 24, 2007 15:55
evaporation and condensation in the VOF model Glev FLUENT 0 December 24, 2004 05:55


All times are GMT -4. The time now is 21:18.